Android Retrofit: The Ultimate Guide

Android Retrofit, a type-safe HTTP client for Android and Java, streamlines network requests by converting them into easy-to-use Java interfaces. This tutorial delves into Retrofit in Android, demonstrating its ease of integration and flexibility in handling API calls. By integrating Retrofit, developers can significantly reduce boilerplate code, making network operations more efficient and readable.

Getting Started with Retrofit in Android

Before we start, you can find others important tuorial for android here . To kick off, add Retrofit’s dependencies in your build.gradle file to include Retrofit and Gson converter libraries, enabling JSON parsing for Java objects seamlessly. You can get the latest version from here:

implementation 'com.squareup.retrofit2:retrofit:2.9.0'
implementation 'com.squareup.retrofit2:converter-gson:2.9.0'
implementation 'com.squareup.okhttp3:logging-interceptor:4.9.0'

Initialize Retrofit in your application:

Retrofit retrofit = new Retrofit.Builder()

Defining the API Interface

Create interfaces for your API endpoints. Retrofit annotations such as @GET, @POST, @PUT, @PATCH, and @DELETE help define how requests are handled.

Making a GET Request

Retrieve data with a simple GET request:

public interface ApiService {
    Call<List<User>> getUsers();

Creating a POST Request

Submit data using POST:

public interface ApiService {
    Call<User> createUser(@Body User user);

Updating Data with PUT and PATCH Requests in Android Retrofit

Modify existing resources with PUT or PATCH:

public interface ApiService {
    Call<User> updateUser(@Path("id") int id, @Body User user);

    Call<User> patchUser(@Path("id") int id, @Body User user);

Using Path Variables of Android Retrofit

For endpoints requiring dynamic segments, use @Path:

public interface ApiService {
    Call<User> getUserById(@Path("id") int userId);

Handling Dynamic Parameters with @FieldMap and @QueryMap

Retrofit allows for flexible API calls with dynamic parameters:

Android Retrofit Using @FieldMap

Call<User> updateUser(@FieldMap Map<String, String> fields);

Utilizing @QueryMap in Android Retrofit

Call<List<User>> searchUsers(@QueryMap Map<String, String> options);

Executing Requests and Handling Responses

Retrofit manages network operations on a separate thread, using enqueue to handle responses asynchronously:

Call<List<User>> call = apiService.getUsers();
call.enqueue(new Callback<List<User>>() {
    public void onResponse(Call<List<User>> call, Response<List<User>> response) {
        if (response.isSuccessful()) {
            List<User> users = response.body();
            // Process the received data

    public void onFailure(Call<List<User>> call, Throwable t) {
        // Handle failure


Retrofit is an essential tool for Android developers, streamlining network operations with ease and efficiency. By following this tutorial, you’ve learned how to set up Retrofit, define API interfaces, make various types of requests, handle dynamic parameters, and utilize path variables. This knowledge will significantly enhance your ability to interact with web services, making your Android applications more powerful and interactive.